To determine whether dietary maniuplations aimed at sustituting meat and other animal proteins with soybean-based products change the biochemical composition of the urine of patients with recurrent calcium oxalate nephrolithiasis in ways that decrease the likelihood of kidney stone formation. Normal volunteers who are subjected to the same dietary manipulations experience similar but quantitatively smaller changes in urine composition. In stone formers, but not in normal individuals, these changes in urine compos. are paralleled by bone resorp.